This invention relates to consolidating an unconsolidated gas-producing sand in which the permeability is layered and the productivity can be impaired by liquid blocking. More particularly, the invention relates to an improved procedure for consolidating such a sand by the process described in the F. H. Meijs and D. R. Davies U.S. Pat. No. 4,061,191. That method relates to consolidating an unconsolidated gas reservoir by treating it to the extent required to ensure the presence of a significant but small amount of water absorbed on the rock surfaces then injecting enough gaseous silicon polyhalide to convert enough of that water to a grain-bonding silica gel to increase the competency without significantly reducing the permeability. The disclosures of the U.S. Pat. No. 4,061,191 patent are incorporated herein by cross reference.
As indicated in the U.S. Pat. No. 4,061,191 patent, numerous procedures have been proposed for utilizing liquid or gaseous silicon polyhalides in a treatment of subterranean reservoirs. For example, U.S. Pat. No. 2,019,908 discloses plugging a subterranean formation by injecting a nonaqueous silicon polyhalide and then allowing water to infuse and react. U.S. Pat. No. 2,469,354 teaches that a gas drive oil recovery process can be improved by injecting a gas which contains a halosilane and causes an oil-wetting of the rocks and/or plugging of a thief zone. U.S. Pat. No. 2,633,919 teaches that a reservoir can be oil-wetted by injecting a nonaqueous liquid containing a hydrocarbon-substituted silicon halide and then injecting water to hydrolyze the adsorbed halide. U.S. Pat. No. 2,808,886 teaches that a gas drive oil recovery process can be improved by including vapors of volatile hydrolyzable inorganic liquid and water in the gas to form permeability controlling or water-layer-plugging solid metal oxides or silica gels. U.S. Pat. No. 3,055,425 teaches that a reservoir can be consolidated and stabilized by injecting a nonaqueous liquid containing a silicon halide and then heating the treated zone to above about 300.degree. F. U.S. Pat. No. 3,087,542 teaches that a water-bearing formation can be plugged by injecting gaseous silicon tetrafluoride to finger through the water and form a radially extensive plug. U.S. Pat. No. 3,090,435 teaches that by injecting a water-in-oil emulsion followed by a nonaqueous liquid containing a silicon halide, an unconsolidated reservoir can be consolidated. U.S. Pat. No. 3,221,505 teaches that a barrier plug can be formed by injecting a water-miscible liquid followed by a gaseous silicon tetrachoride to form a plug along the interface between it and the water. U.S. Pat. No. 3,252,513 teaches that water can be excluded from a well being gas drilled by injecting aqueous ammonia into a water producing carbonate reservoir ahead of an oil solution of silicon tetrachloride.